This application is based on Japanese Patent Application No. 266560/1999 filed on Sep. 21, 1999, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an image processing apparatus for outputting an image by a printer or a display.
2. Description of the Prior Art
When printing out or displaying an image read by a color scanner or a computer graphics, a process is performed as necessary, in which colors of the image data are converted into colors within a color reproduction range that is unique to the output device. For example, there are a first color compression method and a second color compression method. In the first color compression method, a color range of the image data is compressed for every hue so as to meet the color reproduction range of the output device when the output device has a narrower color reproduction range or when the image data include data which are out of the color reproduction range of the output device. In the second color compression method, only the color which are out of the color reproduction range is converted into a similar color within the color reproduction range. A system that can use a different color compression method in accordance with a kind or the number of colors of the image is proposed in Japanese unexamined patent publication No. 8-111786, for example.
In the first color compression method, there is a problem that since the color data of the entire image data are corrected, a process time becomes long though it is suitable for an image such as a full color image or a picture image in which a color gradation is important. In the second color compression method, there is a problem that since only the color which is out of the color reproduction range is compressed, though the process time is shortened, the color gradation is deteriorated. Therefore, a false contour is generated in the border of the compressed color which is out of the color reproduction range and other colors, resulting in a deterioration of the image quality. In addition, when instructing the image output, an operator has to assign the necessity of the color compression and to select the optimal process.
The object of the present invention is to realize an image output system in which many operations are not required for the color reproduction.
An image processing apparatus according to the present invention is used for receiving image data representing an image and for outputting the data to the output device that reproduces the image. The apparatus comprises an attribution controller for deciding attribution of the image in accordance with the received image data, a decision controller for deciding whether the color range of the image is within a color reproduction range of the output device in accordance with the received image data, a color correction controller for performing a correction on the received image data when the attribution controller has decided that the image is not within the color reproduction range so as to make the color range of the image within the color reproduction range and a switching controller for switching the contents of the correction in the color correction controller in accordance with the attribution that the attribution controller has decided.
An image processing method according to the present invention is used for receiving image data representing an image and for outputting the data to the output device that reproduces the image. The method comprises an attribution step of deciding attribution of the image in accordance with the received image data, a decision step of deciding whether the color range of the image is within a color reproduction range of the output device in accordance with the received image data, a color correction step of performing a correction on the received image data when the attribution step has decided that the image is not within the color reproduction range so as to make the color range of the image within the color reproduction range, and a switching step of switching the contents of the correction in the color correction step in accordance with the attribution that the attribution step has decided.